1. Technical Field
The present invention relates to an image reader, such as a flatbed-type scanner.
2. Related Art
In the related art, an example of the image reader is a flatbed-type scanner which includes a reading carriage on which a sensor for reading a document sheet is mounted and which performs scanning in a scanning direction, an annular belt that draws the reading carriage, and three pulleys over which the belt is looped.
In such an image reader, two out of three pulleys are disposed on opposite ends in a scanning region of the reading carriage, and the remaining one pulley is disposed at a position overlapped with the scanning region of the reading carriage, such that the belt is stretched in a triangle (for example, JP-A-2004-133151).
Incidentally, in some cases, the image reader includes a detection unit, such as a reflective optical sensor, disposed on the side opposite to a mounting surface of a document-sheet platen where the document sheet is mounted, in order to detect the presence/absence of a document sheet mounted on the document-sheet platen. Since the detection unit is positioned to be overlapped with the scanning region of the reading carriage, there is concern that the detection unit interferes with the belt stretched in a triangle.